These adorable puppies will grow up to be professional police and military officers. What is that journey like? Well, that depends on what kind of working dog the pupper will be in the future. 

SitStay sorts police dogs into four categories: patrol, drug detection, bomb detection and scent tracking dogs. K9 Global Training Academy adds mines and arson. No matter what category the handler will train their puppy for, all working dogs have to go through beginner obedience training.

What breeds do K-9 units most often train? German Shepherds and Belgian Malinois are the most popular breeds for police dog training. K9 Global Training writes that those breeds are "fiercely loyal, and adjust well to the handler-protection mentality."

Dobermans are also great candidates because of their fearlessness, protectiveness and seemingly never-ending energy. However, they can also be more nervous and easily upset. Perhaps that's why they're not the first choice.

Other four breeds that we can see in the police force are Beagles, Bloodhounds, English Spaniels and Labrador Retrievers. Beagles are excellent sniffers, they often work in airports looking for contraband, weapons and drugs. They're not intimidating, therefore a great tool in places where there are lots of people.

Evidence discovered by Bloodhounds is even admissible in courts, their sense of smell is that good. Police forces use Spaniels to look for explosives and drugs, and the same goes for Labrador Retrievers. However, the latter can also be search and rescue dogs. They're great arson dogs too, because they're highly food or treat-driven. Handlers train arson dogs to detect substances like gasoline, lighter fluid, acetone, etc.

Labrador Retrievers, however, are not great at protecting their handler. That's a job for German and Dutch Shepherds or Belgian Malinois. They are the best patrol dogs. These types of pups get training for protecting their officer and subduing criminals. They also get narcotic scent training as well.

Drug detection dogs have impeccable discipline. SitStay writes that a dog trained in finding narcotics can distinguish between different kinds of drugs. "These dogs could smell narcotics even if you were cooking a steak right next to them, making them an effective detection dog," they write.

Dogs who train to work in bomb detection have to go through an extensive 10-week course. They learn to differentiate between 10,000 smells associated with explosives and are pros at what they do. These dogs can work in airports or other transportation hubs, but the military also uses them in active war zones. Their handler's safety is the first priority for the dog and they can attack with or without command under dangerous circumstances.

What's interesting about these types of police dogs is that they're not food and treat-driven like Labrador Retrievers. These pups are brimming with energy and their reward is most often a toy and praise. "They don't know they're out looking for explosives and we don't expect them to. They love to work more than any human does," say the MTA K9 trainers.

Tracking dogs can help find not only missing people or convicts but also items. This line of work is usually associated with Bloodhounds, but German Shepherds and Malinois can be tracking dogs as well. These dogs can search for hours if not days to find people and evidence based on their scent. However, Bloodhounds can only look for people. That's why police forces more often opt for German Shepherds.

Professionals who train police and military dogs have certain criteria. The pup can't be timid or fearful. "We're looking for a strong, confident dog that also likes to use its nose for hunting. We're looking for <...> a dog that's willing to bite and defend its handler if need be," trainers from Lackland Air Force Base in San Antonio, Texas say.